Contact tabs disappear after sorting data on a tab

This issue can be reproduced in the CiviCRM sandbox by doing the following:

1) Bring up a contact record for any contact.

2) Click the "Pledges" or "Events" tab.

3) Sort the data by clicking one of the column headings, such as "Pledge made" or "Event date"

The data is now sorted, but the tabs for this conatct have vanished.

This was tested under Firefox 6, Chrome, and Internet Explorer 9